• The Vendor's Bazaar forum is for commercial offers and transactions. Only unmoderated members can post here.

    diyAudio provides this forum for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members. Use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Hi-end DSP based multi-channel integrated Preamp/Crossover/DAC project

Jump to Latest
#801
Nice!
Two consecutive 0dB points would also be a good indication but of course there is also the inter-sample clipping thing, so maybe some more complicated method involving interpolation could be used, but would eat up DSP power...)

This is important because even a with a correction that never exceeds 0dB you can have saturation on 0dBfs real world signals when phase is modified, be it with IIR (normal filtering or all pass filters) or FIR (phase linearization).

The reason is quite simple: phase modification will alter temporal positions of peaks at different frequencies, and result in a different summed level. It will be lower than original most of the time, but can also be higher to an extend that is difficult (or impossible) to predict.
In this situation a clipping led is a good indication that the level has to be lowered inside the DSP (or in front of it) for that particular material.

Having volume control at the source or inside the DSP solves this problem, because you almost never approach 0dBfs (and if you do and your system is well adjusted chances are that you also reach territories where you amplifier and/or loudspeakers and/or ears will not be at their best), but having the volume control inside the DAC with integer (or clipped fractionals) data in front of it imposes some more care.
 
#807
cogeniac said:
When you say "the human threshold is in the 1 msec" region are you suggesting that this is the limit of signal period we can hear (seems unlikely) or its it the limit of our ability to differentiate delay? (more likely).

I'm not sure how relevant the latter would be, since we are questioning if one might be able to perceive the existence of the ringing, and the former seems unlikely since we can (ideally) hear sounds up to 20 KHz. A 20 KHz signal would have a period of 50 usec (0.05 sec)..

Scott
Click to expand...

My understanding of the Haas effect is that differnt sounds with wavefronts that comes less than 1 ms appart will be heard as one sound with the same spectral content as the two signals. So preringing 0.1 ms before the square wave will be heard as belonging to the square wave sinuses. (Then I don't think humans can hear the frequencies of the preringing in question)

So, sorry, but I don't think the normal human ear can hear risetimes higher than that of a 20k sinewave.
Torgeirs
 
Last edited:
You must log in or register to reply here.
Top Bottom